Wednesday, January 23, 2013

Wait, There's How Many Independently Funded Studies on GMOs?

I just came across this list of 126 independently-funded peer-reviewed articles on GMOs this morning, and I'm really surprised I hadn't seen it a long time ago. Clicking through some of the studies, they run the gamut of genomic analysis between conventional and genetically modified crops (particularly on unintended alterations of untargeted genes), the potential for transferring antibiotic resistance, the risk of allergenicity, analysis of tissue and metabolites in rats, amount of pesticide use, and the effect of Bt corn and GM soya on mouse testes. In all but a handful of studies, the investigators found no evidence that GM poses an additional risk over conventional farming. Again, these are the independently-funded studies so many critics of the technology have asked for for years. There's simply no excuse for ignoring it.

I didn't see any studies about cassette tape genes. I'd just steer clear for now. (Source)

I've written before about systematic reviews and meta-analyses, and how if you don't look at the full picture, it's extremely easy to cherry-pick to find the results you're looking for. Without really looking too hard, you'll find some studies that contradict the consensus this list represents, as you would expect in just about any field. For instance, one study may say eating eggs provides nearly the same cardiovascular risks as smoking, while a meta-analysis of all prospective cohort studies, including the previous one, on eggs and cardiovascular health representing data from over 260,000 people, shows no additional risk. Which conclusion do you think holds more weight? I can't stress enough that science isn't a push and pull of individual studies floating in a vacuum, it is a systematic way of looking at an entire pool of evidence. It takes work to train yourself to do this. It's just not how we're wired to think, and even people who have been exposed to it still struggle with it, as I see in my everyday experience in evidence-based medicine. People naturally have their preferences, but if there's a way to minimize this effect it's inconceivable to me not to use it to guide our decisions, from adopting a new technology, abandoning existing ones that don't work as well as we hoped, and in the way we determine our public policies.

In my many, many conversations on GMOs, I've found that confirmation bias isn't the only barrier, there's also a significant amount of conflation going on between what's specific to GMOs and what is just poor agricultural practice. For example, it's quite clear that pesticide resistant weeds (aka superweeds) are popping up on farms around the U.S. Certainly, growing Roundup Ready corn would logically facilitate the overuse of a single pesticide on a single area, but resistance will occur anywhere there's over-reliance on a single pesticide, and it's up to the particular farmer to rotate their crops to avoid this. Just because many have failed to do it doesn't mean that GMOs are the primary problem. On the spectrum of possibilities of genetic modification, in my view pesticide resistance is securely on the bottom, but let me put it this way: if we just simply banned them, totally removed pesticide resistant crops from all farms in the U.S., would we solve the problem of superweeds for all time? Obviously not. For every potential risk you've heard of about GMOs, ask yourself the same question. You'll almost always find that the problem comes down to general issues of large-scale agriculture.